"Finite element analysis" is a mathematical approach to solving large (complex) problems. Generally the subject is segmented or discretized into many pieces that have closed form solutions. That is, each piece is definable by a linear equation, and hence is a "finite element." Collectively, the linear equations of the pieces form a system of equations that are simultaneously solvable.
Computer programs for simulating finite element analysis in various applications exit. For example, finite modeling programs are used by design engineers. Typically many thousands of elements are created to model a subject object and in particular three dimensional objects. For each element, there is geometric information such as an (x, y, z) coordinate at a point in the element, an element type, material property, stress value, displacement, thermal value, etc. Such information is definable by linear equations for the elements. To that end, finite analysis is employed to model the subject object.
Example finite modeling programs include: ANSYS by Swanson Analysis Systems Inc. of Houston, Pa; SUPERTAB by Structural Dynamics Research Corp. of Ohio; and PATRAN by PDA Engineering of Costa Mesa, Calif.
One disadvantage of such finite element modeling is that the large number of elements presents a problem in verifying geometric correctness of the model and resulting element information in the model. That is, one need in finite modeling computer programs is a very fast interactive way for an engineer to view a model and make queries, preferably by directly pointing with the screen cursor through mouse operations. Typical information to be returned by query functions include the geometric information and physical/material property information. Ideally a "direct manipulation" interface is desired, so that the engineer can feel as if he is pointing to locations on an object in his hand.
Some existing finite element modeling computer programs, such as PATRAN by PDA Engineering of Costa Mesa, Calif., allow data queries. In particular, these programs use simple linear searches through a geometry database. Typically, an engineer using such computer programs type a command declaring that some number of elements are to be "picked" and that designated information regarding the elements is to be returned. Using the mouse, he then moves the screen cursor to a point on the displayed model and operates a mouse button; after a few seconds the computer program finds the elements nearest the cursor and outputs the requested information. Often due to the clutter of a complex, 3-dimensional model on a two dimensional screen view, an incorrect element is picked, requiring another try and another several seconds wait. This is most serious on very large models where on the order of tens of thousands of queries need to be done, since these models are the slowest to process.
Thus, the existing query techniques can be very slow since thousands of elements may need to be checked for a "hit." Because of this bottleneck, finite element modeling computer programs do not provide a lively human interface for query functions. Accordingly, there is a need for a better interactive way for an engineer to view a model and make queries regarding the elements of the model.